Note: The following is only my opinion. YMMV.
Here’s the URL of the auction mentioned above by Anon (NOT me). I like mine and wouldn’t part with it.
http://cgi.ebay.com/Mont-Bell-Ultra-Lightweight-Down-Inner-Jacket-Montbell_W0QQitemZ4434621819QQcategoryZ57988QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
BPL reviewed this jacket HERE
AND HERE
Here’s a link to the Montbell website product page for this jacket
It is a very nice jacket. It doesn’t have much loft. However, under a wind shell, I find it warm down to the low twenties deg. F with minimal activity At these temps and above it would be too warm to wear while hiking. In my opinion, it’s only advantage over synthetic insulated jackets is that it shaves one or more ounces off the weight of a similarly insulating UL synthetic jacket. In dry weather, I wear it alone in the upper twenties and thirties deg. F.
Keep in mind that this jacket is an “inner” jacket and so lacks pockets (as many of them do – pockets are generally inaccessible anyways if a shell is worn over them).
This jacket is also treated with a DWR finish. It also has a plastic snap closure instead of a zipper. This is fine, IMHO, but take more time to close than a zipper – partly because…There are enough snaps so that the proper ventilation can be achieved. IMHO, it is a very nice jacket. IMHO, definitely worth full price if new (i haven’t read the eBay to see if it’s new or used).